Unjust enrichment: Some items to consider: Use of statutory powers to gather evidence
The fact that the burden of proof is on us in unjust enrichment cases does not mean that we have to make our case without recourse to the claimant’s records. We are entitled to gather all the information and documentation that we think we need from the claimant in order to inform our decision.
If a claimant fails or refuses to produce the documents or paperwork that you ask for to build a case for, or against, unjust enrichment, you are entitled to draw reasonable inferences from the information or evidence that you have before you.
However, such a stance may attract criticism from the tribunal and compromise our case if we have not made use of our statutory powers to require the production of relevant records or the furnishing of relevant information (See Schedule 37 to the Finance Act 2008).
If, for example, a claimant is being obstructive or uncooperative, you should consider using these powers to obtain the documents or information that you need. If the claimant still refuses to co-operate, you can then reasonably form a view on the basis of what documents or evidence (circumstantial or otherwise) that you do have.
Recent case law has clarified this aspect of unjust enrichment. In Weber’s Wine World Handels GmbH & others -v- Abgabenberufungskommission Wien, CJEC Case C-147/01,  BTC 8019 and Commission of the European Communities -v- Italian Republic, CJEC Case C-129/00 (cited with approval by the High Court in C&E Commrs -v- National Westminster Bank Plc,  EWHC 1822 (Ch);  STC 1072;  BVC 633) the European Court of Justice held that, whilst the burden of proof lies on the tax authorities, they cannot be expected to discharge that burden without the co-operation of the taxpayer.
In the absence of any such co-operation, HMRC and the Courts are entitled to draw reasonable inferences from the evidence that they do have before them and from the taxpayer’s refusal to co-operate.